The present invention relates to a thermal transfer printer that will transfer an imaging compound, such as a wax, wax resin or wax resin composite, or a dye from a carrier ribbon, film or web to a substrate, as shown, a compact disc, using linear printing across transverse (chordal) lines on the circular disc, which vary in length as the disc progresses underneath the thermal printer head. A platen roller is mounted so that it pushes the disc carrier and disc against the printhead at a desired force for adequate printing for different line lengths.
Thermal printing technology for compact discs (CDs) and recordable compact discs (CD-Rs) incorporate pivotally mounted heads and linear platens with resilient surfaces and expensive clamping mechanisms for the CD. Loading thermal ink ribbons is cumbersome, inconvenient and time-consuming because the ribbon must be threaded through the rollers and the printhead and manually re-attached to a take-up core.
Current technology for printing onto CDs utilizes expensive head actuating and force modifying mechanisms. The printhead is moved on pivotally mounted arms that extend substantially beyond the envelope of the printhead, with a linearly driven carriage that has to hold the disc over an expensive, flat resilient surface with a clamping device that moves with the carriage. Threading the ribbon through the printhead and mounting ports of the presently available printers is a tedious job which includes taping the ribbon to the carriage, then taping the ribbon after the carriage is driven into the printer. This leads to large, high-cost thermal transfer CD, CD-R and digital video disc (DVD) printers. It is desirable to substantially reduce the size in order to take less space for the CD printers, as well as manufacturing costs and user interaction.